This invention relates generally to a closure for the filler pipe of a vehicle fuel tank which is adapted to be filled by a pump nozzle inserted into the outer end portion of the filler pipe.
More specifically, the invention relates to so-called capless closures of the type which eliminate the need for manually removing a gas cap to fuel the vehicle and then replacing the cap when the fueling is complete. One such closure is disclosed in Davidson U.S. Pat. No. 2,503,031, that closure including a spring-loaded flapper valve which is adapted to be pivoted to an open position by the fuel nozzle when the nozzle is inserted into a fill opening in the closure. Gravino U.S. Pat. No. 5,145,081 also discloses a capless closure with a spring-loaded flapper and, in the case of the Gravino closure, the flapper is adapted to be selectively locked and sealed in its closed position relative to the fill opening in order to prevent moisture and road contaminants from entering the tank.
Although not specifically disclosed by the Davidson or Gravino patents, capless closures of the foregoing type frequently are attached to the filler pipe by screwing the closure onto the pipe. Unless the closure is protected by a locked fuel door on the vehicle, there has been no provision in prior commercial capless closures for preventing theft of the closure by a person who simply unscrews the closure from the filler pipe. In a commercial sense, capless closures are relatively new and are becoming increasingly popular in general and particularly on rental cars. Certain persons who rent such cars are attracted by the uniqueness of the closure and frequently remove the same for use on their own car.
Also, prior commercial capless closures make no provision for preventing unauthorized siphoning of fuel unless, again, the closure is protected by a locked fuel door. Accordingly, such closures lead to the theft of fuel.